The key to that cold sear technique is that the chef is using hot metal in contact with the steak surface (i.e. conduction energy transfer). The cook is almost entirely via conduction. The classic method (pan then oven) cooks first by conduction, then second by convection (hot air).
Conduction delivers heat energy much more efficiently than convection (hot air) or IR radiation. So you can build up a better Maillard crust at a lower temp.
And heat is being transferred to the inside of the steak by efficient conduction as well. Basically, the outside of the steak cooks the inside of the steak via conduction energy transfer. Because of the efficiency of conduction, you can use a lower temp and still get the job done. And the frequent flips keep the conduction/sear effect from going too far. Which is easy to do when using hot metal.
That conduction-based technique should work well with any griddle, flat top, cast iron pan or (dare I say it) the flat side of GGs. Less well on a gasser producing mostly convection heat -- which is why many gassers now have extra sear burners or IR burners.
Charcoal cooks mostly via IR radiation, which is a different ballgame.